Writing instrument



2 Sheets-Sheet 1 INVENTOR. John C ,WEZ/ZZ,

Sept. 27, 1949. J. c. WAHI.

WRITING INSTRUMENT Filed Aug.r s, 1945 E S. Nm

M M M N @n o NJ. m Nm vmwmm Sept. 27, 1949. J. c. WAHL 2,483,329

WRITING INSTRUMENT Filed Aug. e, 1945 2 sheets-sheet 2 1N V EN TOR.

A #fwd/W @W A? um Patented Sept. 27, 1949 gisant WRITING INSTRUMENT John C. Wahl, Chicago, Ill., assignor to Eversharp, Inc., Chicago, Ill., a corporation of Delaware Application August 6, 1945, Serial No. 609,277

1 Claim. (Cl. 1Z0-42.03)

This invention has to do with writing instruments of the type in which the tip is retractable, and is particularly concerned with an improved ball point pen of this type.

One of the principal objects of the invention is to provide a pen of the character described in which the tip containing the writing ball will be either projected if in a retracted position or retracted if in a projected position by merely pressing in on a novel push button mechanism located in the rear end of the pen.

Another important object of the invention is to provide an improved rell ink cartridge for use in a retractable tip pen.

Another object is to provide an improved pen structure for the reception of both a refill ink cartridge and a tip projecting and retracting mechanism.

Other more specific objects and advantages of the invention will be apparent to those skilled in the art upon a full understanding of the construction, arrangement and operation of the new writing instrument.

One embodiment of the invention is presented herein for the purpose of exemplication, but it will of course be appreciated that the invention is susceptible of incorporation in other structurally modied forms coming equally within the scope of the appended claim.

In the accompanying drawings:

Fig. 1 is an enlarged side View of a ball point pen constructed in accordance with the inven- Fig. 2 is a longitudinal section through the pen, showing the writing tip of the pen in its projected position;

Fig. 3 is a similar section, showing the tip in its retracted position; I

Fig. 4 is a fragmentary longitudinal section through the casing of the pen at the location of the projecting and retracting mechanism, taken at right angles to Fig. 2, showing the mechanism in elevation in the projected position of the tip;

Fig. 5 is a side view of the housing for the mechanism, with the several associated parts removed, viewed from the same direction as Fig. 4;

Fig. 6 is a diierent side view of the housing for the mechanism;

Fig. 7 is a greatly enlarged side view of the ratchet wheel;

Fig. 8 is an edge view of the same;

Fig. 9 is a side view of the stationary wheel engaging tube which surrounds the housing for the mechanism;

Fig. 10 is a side view of the rell ink Cartridge 2 and the ball point writing tip to which the cartridge is secured; and

hFig. 11 is a side view of the cartridge alone, w1th the ink feeding nipple of the cartridge encased within a protective closure.

As will be observed in the drawings, the pen includes primarily a casing I0, a refill ink cartridge II, a writing tip I2, a mechanism I3 for projecting and retracting the tip, and a push button I4 for operating the mechanism.

The ink used in the pen is a thick semi-fluid mk having somewhat the viscosity of ordinary pninters ink. This ink is transferred to the paper or other material to be written on by the rolling action of a very small ball I5 which is 'journaled in a. socket located in the extreme front end the tip I2.

The tip I 2 is of elongated tubular form and tapers `at its front end toward the ball I5. Immediately behind the ball the tip contains a bore i I6 of even smaller diameter than the ball, which bore terminates but a short distance rearwardly of the ball in an annular rearwardly facing seat Il--all within the end of the tapered portion of the tip. The tip I2 is removably telescoped over a slender nipple I8 which projects forwardly from the body of the cartridge II. The nipple I8 contains a bore I9 in register with the bore IB and tapers toward its front end, at which end it is provided with a small annular face 20 for huid-tight abutment with the annular seat I 'I. The face 20 is clamped against the seat l1 by screw threads 2 I on the inside of the rear end of the tip I2 which engage with corresponding threads 22 on the outside of the nipple I8 near the base of the latter.

The cartridge I I, to which the tip I2 is thus iixedly secured in the operative position of the pen, contains a long tortuously arranged passage 23 in which the supply of ink for the pen is held. One end of the passage 23 communicates with the rear end of the bore I9 in the nipple I8- which bore is quite small at its front end but substantially enlarged toward its rear endwhile the other end of the passage 23 is vented to the atmosphere at 24.

Y The tip I2 is'reciprocally mounted in a bore 25 in the front forwardly tapering end portion 26 oi the casing I0, and the cartridge vIl is similarly mounted in the ca-sing lil rearwardly of the portion 2S. A coil spring 2 encircles the tip I2 within an enlarged portion 28 of the bore 25 and is compressed axially between an annular shoulder 29 in the bore 25 and an annular shoulder 30 on the nipple I8 at the point where the latter connects with the body of the cartridge I I. The spring 21 serves to press the cartridge II and tip I2 rearwardly within the casing I from the projected position of the tip shown in Fig. 2 to the retracted position of the same shown in Fig. 3.

The mechanism for eiecting the projection and retraction of the tip I2 relative to the casing le includes an elongated housing 3l which bears at 32 against the rear end of the cartridge Il, and, like the cartridge, is slidably mounted in the casing is. The housing 3l, which is located near the rear end of the casing Il), is provided at its rear end with a screw threaded stud 33 which engages with a correspondingly threaded recess 3d formed on the inside of a stud 35 on the push button Iii, thus connecting the housing 3I iiXedly with the button III. The housing 3l is provided with a longitudinally extending slot 35, and a ratchet wheel 21 is rotatably mounted on a cross pin 58 in the slot. Every other tooth 39 on the wheel 3l extends the full width of the latter, while each intervening tooth te extends but half such width, for a purpose which will be explained later. The wheel 31 is intended to turn only in the direction indicated by the arrows in Figs. 2 and 3, and is prevented from turning in the opposite direction by a pawl lll. The pawl fil is positioned in the slot 3G and is pivoted on a cross pin 42. A reversely bent leaf spring 43 is compressed between the pawl ll and the rear end of the slot 36 in the housing and presses the pawl 5I into one-way clutched engagement with the teeth on the wheel.

The housing SI, which carries both the wheel 31 and the pawl LSI, and which reciprocates as a unit with the push button I4, is surrounded by and slides within an open ended tube is formed of spring material. The tube lll is fixedly secured at its rear end within a recess formed in a stationary cap 45, and the cap d is screwed tightly into the rear open end of the casing I0. The tube is is held against turning in the cap 45 by burring the edge of the cap at i6 into a small opening d1 cut in the tube. The cap 45 contains a bore i8 in which the stud 35 on the push button I Iil reciprocates. The button I4 is provided with a forwardly extending rim i9 which slidably telescopes over the stationary cap 45 and over the rear end of the casing IQ. The tube lill is provided opposite the slot 36 in the housing 3l with an inturned tongue 5B which slidably engages within the slot and prevents the housing Jfrom turning relative to the casing I5. The

tube lil is also provided forwardly of the tongue 55 with an elongated opening 5l, with a locking projection 52 at one side only of the opening, and with a rearwardly extending spring finger 53 at the front end of the opening. The finger 53 is depressed at its rear end into an inclined recess 54 formed on the underlying portion of the housing 3l. The front edge 55 of the projection 52 is adapted to abut with the wide teeth 32 of the wheel `3l but such edge does not extend laterally across the path of the wheel far enough to engage with the narrow teeth 40 and in consequence clears the latter.

The mechanism I3 for projecting and retracting the writing tip l2 operates as follows:

Starting with the tip I2 in its retracted position, as shown in Fig. 3, depression of the button IA; acts directly through the housing SI of the echanism to project the tip from the position shown in that view to a position a little beyond that shown in Fig. 2. As the housing 3l moves forwardly during the projection of the tip the spring finger 53 on the stationary tube 44 engages with and rotates the ratchet wheel 31 through an angle corresponding to the distance between adjoining teeth, from a position in which one of the narrow teeth is disposed in the plane of the projection 52 on the tube '44 in a position in which one of the wide teeth 39 is disposed in that plane. Release of the button I4 then permits the tip I2 to recede slightly until the then laterally exposed wide tooth of the wheel engages with the front edge 55 of the projection 52, whereupon further rearward movement of the housing I3 is solidly blocked and the tip I2 is brought to rest in the projected position shown in Fig. 2, in readiness for use.

To retract the tip I2 it is merely necessary to press the button Ill a second time. This initially results in the tip being again projected a little beyond the position shown in Fig. 2. During this projection one ofthe teeth of the forwardly moving wheel 31 is brought into engagement with the finger 53, andthe latter causes the wheel to turn the distance of another tooth, thereby bringing one of the narrow teeth 4I) into the plane of the locking projection 52. In this position of the wheel 31 the narrow tooth will clear the projection 52 and can move rearwardly past the edge 55 of the same. Release of the button I4 then allows the tip I2 to move Vrearwardly under the action of the coil spring 21 into its fully retracted position, in readiness forV the next projecting operation.

The casing I0 is preferably made intwo sections, which sections are screwed together at 56 and can beeasily taken apart when a full ink Y cartridge is to be substituted for an empty one.

To replace the cartridge II it is merely necessary to unscrew the two sections of the casing I0, slide the empty cartridge out of the front section of the casing, unscrew the writing tip I2 from the nipple I8 of the cartridge, screw the same tip onto the nipple of the new cartridge, slide the same into the front section of the casing, and replace the rear section.

Before applying the tip I2 to the nipple of a new cartridge a temporary closure 51 on the nipple is rst removed from the same. The closure 51, which is illustrated in Fig. 11, can then be discarded. The screw threads 22 which are used on the nipple I8 for securing the tip I2 in position are also used for retaining thevclosure 51.

I claim:

In a writing instrument, a hollow casing provided at its front end with a forwardly opening bore and at its rear end with a rearwardly opening bore, a writing tip reciprocably mounted in the-front bore for movement between a retracted position and a projected position, a push button reciprocably mounted in the rear bore, and means within the casing operated by the button and acting upon the tip to alternately project and retract the tip upon successive forward movements of the button; said projecting and retracting means including a rotatable ratchet wheel which reciprocates with the button and is rotatable in but one direction, a stationary element in the casing which turns the wheel every time the wheel moves forwardly, and a second stationary element in the casing which holds the wheel against rearward movement by engagement with predetermined teeth thereof every other time the wheel starts to move rearwardly.

JOHN C. WAHL.

(References on following page).

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date Matsui Nov. 14, 1916 Gartner July 17, 1923 Pollock May 29, 1928 Number 

